1. Technical Field
This invention relates to copy protection of software and more particular to copy protection of software for use in a private branch exchange switch.
2. Description of the Prior Art
Today's private branch exchange (PBX) switches are relatively complex systems that require extensive customized software to handle the many features available to users operating telecommunications equipment within these systems. This software is normally acquired by a purchaser from a vendor or manufacturer of the system through the purchase of a software license when the PBX switch is initially installed, or when subsequent upgrades to the software are acquired.
A secondary market has evolved for some PBX switches. In this market, a pirate purchases the switch from a legitimate owner, receives physical possession of the customized software for the switch and relocates the switch in a different central office serving area. The pirate next attempts to use the customized software for the switch in violation of the software licensing agreement between the vendor or manufacturer of the switch and the original purchaser of the switch. The impact of this secondary market can easily amount to hundreds of thousands of dollars in loss revenue to developers of customized software for PBX switches.
A number of software locking arrangements have emerged for guarding against software piracy of customized software for use with a PBX switch. A first well-known arrangement is the hardware key arrangement. The hardware key arrangement requires firmware that plugs into a processor that is associated with the switch software. The firmware is designed to be difficult to clone and to reverse engineer. The copy protection is provided by virtue of the difficulty in reproducing the firmware or hardware key.
A second well-known arrangement for the protection of customized software for use with a PBX switch is the license manager arrangement. The license manager arrangement is a software based arrangement wherein the vendor embeds encrypted registration information in the customized software. This registration information may be, for example, either the customer's licensed serial number or the customer's site location. Any attempt to operate without entering this encrypted registration information results in the protected program ceasing to operate.
Although both of these software locking arrangements provide reasonable protection against the unauthorized use of customized software for a PBX switch appearing on the secondary market, each of these arrangements have significant implementation costs as well as continuing administration costs. This is due mainly because of the requirement for maintaining and staffing databases for these arrangements at the PBX vendor's centralized locations.